This invention relates to an operating mechanism of a multipole circuit-breaker having a molded insulating housing, said mechanism being mounted between two parallel support plates and comprising:
a manual operating handle with an extended base located inside the housing between the mechanism and a cover of said housing, PA1 a toggle device associated with an automatic trip lever and with a switch bar common to all the poles, PA1 a stored energy spring fitted between the handle and the knee of the toggle, PA1 a device for latching the trip lever in the set position, PA1 a trip bar which can be either in an "inactive" position or in a trippped position to respectively latch and unlatch the trip lever, PA1 and tripping means operating with trip bar when a fault occurs or an external order is given.
Such a known circuit-breaker is disclosed in U.S. Pat. No. 4,274,069.
The handle is supported by an auxilary lever pivoting on a fixed pivot pin secured to the mechanism support plates. The handle trajectory has a small pivoting radius due to the presence of the axis of the lever inside the housing. The trip bar is mounted outside the trajectory of the handle, resulting in an increase in size of the insulating housing.
The presence of this pivoting lever also increases the friction of the movable assembly requiring a great deal of effort to operate the handle.
The object of the invention is to provide a circuit-breaker with a compact housing fitted with a simple mechanism permitting reduced friction of the moving parts of the movable assembly.